Flamethrower Injector Issues?! HELP!!!
 

Hello all. I own a 94 4Runner that has been a battle since I bought it.I recently bought a set of the tanish? Flamethrower injectors hoping to eek out some more power and help gain low end torque for towing a trailer. Install went fine, pretty straight forward. Truck drove great for 3 days. 4th day when I come to a complete stop the truck idles VERY hard. Sounds and feels like it's going to stall out. But it won't. When I go to accelerate it runs GREAT. Better than before BY FAR. After the idle issue I removed both battery cables for about an hour in hopes of resetting the ECU to adjust to the added fuel.

I am thinking it is getting too much fuel for idle. I checked my timing, I'm still 11 degrees BTDC like it has been since I rebuilt the motor. Didn't have any idling issues prior to the injector install.

Truck has a S&B Intake and a custom made 2.5" High-Flow Cat/Cat-Back Exhaust.

Possibly too much fuel for not enough mods???? I need some help here, truck is my daily and I am worried it is going to leave me stranded sometime soon.

Truck has NO CEL's.

Thanks,

Not sure if that year has OBD2 diag port, but if it does, scan it or rent a scanner and watch the O2 reading. It should bounce up and down a lot when working correctly. The O2 basically adjusts the default fuel mapping based on what it sees, so it's possible it's reading a bit off, but not enough to throw a code. My dad's T100 was similar, no CEL, but was getting terrible mpg (like 13mpg) and he scanned it and O2 wasn't working most of the time. Replaced it and it runs a lot better now, still not perfect though. That's a 3.4L though

If it was a carb, then it would make sense you'd need more mods for the exhaust and fuel mods, but the EFI system should be able to adjust enough to run correctly with the mods (within reason at least).

Oh, be sure if you do replace the O2, to get a good Japanese brand one, not the bosh one. I've seen it reported a few times around having problems with them.

no OBD2 on the 94. they started that with the 2/3rz and 5vz motors in the third gen runners and first gen tacomas.

space-junk is correct.

No OBDII port, not until 3rd Gens IIRC.

Forgot to mention, truck had a brand new O2 Sensor put on \when the exhaust was done. Maybe 500 miles ago.

Anymore suggestions?

Did you try adjusting the idle screw up a bit? Seems a little bit odd that it ran fine for 3 days, but I don't know maybe it takes a certain number of engine starts for the ECU to fully adjust to the new readings. Did you remove the battery cables to reset ECU after installing the Flamethrowers?

Yes & Yes. I adjusted the idle screw. Got it to live around 790-820 I know 800 is MFG spec. And Battery Cables were left off for about an hour.

I have flamethrowers, I put them in, along with headers, new cat and a bunch of head work. I have always felt they were too rich at idle. A trip to a Dyno confirmed that. At cruise they were near perfect. Since installing in my 4runner the exhaust really stinks when the engine is cold. I am considering cleaning/rebuilding the stock injectors and putting them back in to see if these problems go away.

I noticed in the FSM there is a section to adust for HC at idle. I didn't really read thru it as I have no way to measure any changes unless I pay for some more dyno time.

Is this the 3.0 or 22re? I have Flamethrowers in my 22re, idles great. Are you sure you don't have any vac leaks?

3VZE Sorry I should've specified. No VAC leaks to my knowledge.

Probably a good idea to check though. On my other cars I made something I could place into the intake system after the MAF/VAFM with a tire valve JB Welded in. Then put a tire gauge on and run air through the system.

Anyone have any better ideas on this vehicle before I got buy parts and make something like that up?

FACOOK1: Appreciate the insight, I was curious if they ran rich, but this is REALLY rich. Plus everyone spoke so highly of the newer ones. I read a ton of reviews and not one person said anything so it seems off. Gas Mileage is also complete ˟˟˟˟ now as well.

Also VAC leak seems highly unlikely but I will check. Car would've idled bad on the old injectors if that is the case. And it pulls fine.

I feel like I need the ECM/ECU to adapt to the increased amount of fuel and I would be fine, but for whatever reason it is not.

Also this morning on my way to work, no idle issues, it is very sporadic and irritating.

Still appreciate all comments and insight.

I have the 3vze also. I didn't have any idle issues immediately after the rebuild but is seemed rich. I have since developed an idle issue which I mostly fixed by adjusting the TPS. The issue hasn't completely gone away but at least the engine isn't stalling.

I mention this because you said it ran fine for 3 days. Maybe it isn't the injectors at all. I would pull the throttle body and check that the TPS is set correctly. Lots of info in this site on how to do that.

While you have that out you can make sure the cooling passages are clear. If they are clogged it can affect the idle apparently. Mine were clear.

Cook: I can do that as well. Still seems off. If I added a turbo, yes. Other issues that were mild before may start showing them selves with more air, etc. However, with swapping injectors nothing else is changing. Doesn't seem viable that the TPS is having issues after an injector swap. It wasn't touched or altered.

However I will check that as well as run some vac leaks just to cross it off of my list.

I am also curious if due to you having Headers, and the heads worked if it doesn't affect you as well.

I would love some input from other guys running them with similar to me, (basic) mods.

Yes, this is why I can't confirm anything, I changed so much at once. If I change back to the stock injectors anytime soon I will let you know.

Awesome. That is a piece of assistance. I will work on the vac check and possibly the TPS this weekend.

Anymore insight is welcome all.

Regarding the TPS, I never touched the TPS since I bought the vehicle 4-5 years ago. I don't know how it got out of adjustment but after I cleaned and adjusted it it made a huge difference. Maybe its going bad. Anyway I just wanted to make the point that it could be coincidental that the problem started after the injectors were installed based on it running fine for 3 days.

What effect does resetting your fuel trim, unplugging A battery cable or pulling EFI fuse, have? (Note A battery cable, if you unplug both the capacitor has no drain path and will take infinitely longer to discharge and reset the ECU learned trim.) Does it then run "normal" for a while?

The Asnu/flamethrower injector is about ten percent increased flow. This is well within the ECU trim range of about twenty percent. The "benefit" is in the newer style spray pattern, the flow increase gets trimmed out..

Are you monitoring the VF signal voltage in the diagnostic port? If not start there by recording voltage as you drive, then reset the ECU trim and monitor again. Process is covered in the manuals, yours is I believe new enough to also have the te2 proceedure which gives another option iirc.

How should I go about resetting the ECU so it can re learn the fuel trims then?

How do I record VF Signal Voltage?

Thank you for your insight

I believe you just pull the EFI fuse for some amount of time. I want to say 30 seconds but I am not positive.

Correct, battery positive terminal or efi fuse for at least thirty seconds (temperature dependant, cold takes longer)

VF signal is documented in your manual, as I said. In short you plug a volt meter into the vf1 port on the diagnostics. It will have different output based on which test (Te1,Te2, or none) terminal is active.